Fbank l



F. L. POPE.

ELEGTRIGAL CONDUCTOR.

(No Model.)

No. 294,148. Patented Feb. 26, 1884.

INVENTOR f'rcm/c 'L .fo e, By hzLs Afzm-neys WITNESSES a QM;

UNITED STAT S;

PATENT @FMCEQ FRANK L. POPE, OF ELIZABETH, NEW JERSEY, ASSIGNOR TO THEPOSTAL TELEGRAPH AND CABLE COMPANY, OF NEW YOBIL.

I ZLEGTRiCiAL coNoUcToa.

SPECIFICATION forming part of Letters Patent No. 294,148, dated February26, 1884.

- Application filed June 2, 1883. (No model.)

To all whom, it may concern:

Be it known that I, FRANK L. Porn, a citizen of the-United States, and"a resident of Elizabeth, in the county of Union and State of NewJersey, have invented certain new and useful, Improvements in ElectricalConductors, of which the following is a specification. My inventionrelates to conductors designed for the conveyance of electricalcurrents, and more particularly to a certain class of compoundconductors in which one metal selected, primarily, on account of itshigh coefficient of tensile strength is mechanically combined'withanother metal possessing high electrical conductivity. I My invention isespecially designed to be used in connection with systems of electriclighting and electrical power transmission, or wherever it is necessaryto convey electric currents of large volume. In such systems it hasheretofore been usual to employ solid cylindrical copper conductors oflarge diameter, which, having insufficient elasticity and tensilestrength in proportion to their weight, are liable to stretch or breakwhen suspended between distant points of support.

My invention consists in a compound conductor composed of a centralmetallic core of adequate tensile strength, which core is preferably ofsteel, closely coated, by electroplating or other ise, with a continuousenvelope of a suitable highly-conducting metalsuch as copper-randsurrounded by one or more conductors of the same metal as that whichforms the coating or envelope of the central steel core, or of someother metal having approximately the same electro-motiveproperties.

The particular subject-matter claimed will a be hereinafter specificallydesignated. a

My invention is represented in the accompanying drawings, in whichFigure 1 is a transverse section, and Fig. 2 a longitudinal View, of oneform of my combined conductor. Referring to the drawings, A is a centralcore, which I prefer to make of a tough and properly-tempered steel, theobject in view! being to "obtain therein a high coefficient of tensilestrength. l

ciently thick to prevent any possible access of moisture to the core;otherwise a local electrolytic or galvanic action will be set up betweenthe dissimilar metals by the action of such moisture. It is thereforepreferred to place this metal upon the core by the wellknown process ofelectro-deposition, although in some instances it may be applied bymechanical means. 14

It will be understood by those versed in the art that no local galvanicaction will be set up between the outer wires, 0, and the envelopesurroundingthe central core, inasmuch as the contact of similar metalscannot give rise to. an lectro-motive force, nor produce electrolyticaction.

The central core may be constructed to give any requisite-tensilestrength, so that the cable or strand may be suspended betweenfarseparated points. The core, while serving primarily to give thenecessary tensile strength, also materially increases the conductivityof the complete strand.

The surrounding wires may be of any convenient size or number, eithersix-or eighteen being in most cases preferable numbers.

I claim as my invention 1. The combination, substantially ashereinbefore set forth, of a central core formed of metal .having a highcoefficient of tensile strength, a continuous metallic coating ofgreater specific electrical conductivity than the central core closelyenveloping the same, and one or more conductors formed of a metal havingapproximately the same electro-motive properties and conductivity as thecoating laid about said coating and its inclosed central core.

2' eelmne v 2. The combination, substantially as here-. scribed my namethis lst day of June, A. D.

inbefore set forth, of a central conductor. of 1883. p

steel closely enveloped in a; continuous coating of copper, and one ormore conductors of} FRANK POPE 5 copper laid upon or aroundthe steeloon- Witnesses:

duotor and its exterior envelope. DANIEL W. EDGECOMB,

In testimony whereof I have hereunto sub- 1 CARRIE E. DAVIDSON.

